Difference between revisions of "84PCE:Ports:0028"
From WikiTI
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=== Bit [0] === | === Bit [0] === | ||
Latches value written, no apparent effect. | Latches value written, no apparent effect. | ||
| + | |||
| + | Used by OS on Python Edition. | ||
=== Bit [1] === | === Bit [1] === | ||
Revision as of 21:17, 28 June 2019
Synopsis
Port Number: 0028
Function: Flash Protection Status
Details
Flash is unlocked if both bits 2 and 3 of this port are set.
Bit [0]
Latches value written, no apparent effect.
Used by OS on Python Edition.
Bit [1]
Always 0, writes do not latch.
Bit [2]
Can be written freely (under the usual privileged port constraints).
Bit [3]
Can be cleared by writing a 0. Gets cleared any time unprivileged code is executed or port 6 bit 2 is reset. Fetching a flash unlock sequence (F31800F3F3ED7EED56ED3928ED3828CB57) that ends in privileged flash while port 6 bit 2 is set is the only way to set it.
Bits [7:4]
Writes do not latch, no apparent effect.
